Although Google Maps and Bing Maps seem to garner much attention for their mapping APIs, this latest push by ESRI to promote its equivalent APIs does a nice job of highlighting how the APIs can be used in various practical ways. The code samples are fairly comprehensive (check out the JavaScript sample code), and they include straightforward examples for a variety of tasks, including basic map setup, geocoding, and utility methods (such as measuring distance and buffering).

The samples gallery provides easy access to several different examples of how the APIs can be used with the JavaScript, Flex, and Silverlight APIs. The screenshot below shows a sample Silverlight app that incorporates several external data layers, including earthquakes and weather.

In addition to the samples, ESRI also provides access to a few base map and demographics map layers that can be incorporated easily via its APIs. The data is available via a RESTful web service that can output data in a variety of formats, including KML. Here is a link to the reference page for a map layer for U.S. unemployment.

As we previously covered back in late July, ESRI has made its JavaScript API free in an effort to gain more momentum with developers. It's still too early to tell whether this new strategy is working, but the new site does provide some good food for thought and inspiration for developers interested in working with map mashups.